Strontium \({ }_{38}^{90} \mathrm{Sr}\) là một trong số các bụi phóng xạ nguy hiểm từ các vụ nổ hạt nhân. Chu kì bán rã của \({ }_{38}^{90} \mathrm{Sr}\) là \(T=28,8\) năm. Strontium khi bị bò ăn phải, sẽ tập trung trong sữa của bò và sẽ được lưu lại trong xương của những người uống sữa bò đó. Strontium \({ }_{38}^{90} \mathrm{Sr}\) khi nằm trong xương sẽ phát ra các tia phóng xạ có năng lượng lớn, phá hủy tủy xương và do đó làm suy yếu sự sản xuất tế bào hồng cầu. Strontium \({ }_{38}^{90} \mathrm{Sr}\) có khối lượng mol là \(M=90 \mathrm{~g} / \mathrm{mol}\). Lấy một năm có 365 ngày. Số Avogadro là \(N_{\mathrm{A}}=6,02 \cdot 10^{23} \mathrm{~mol}^{-1}\).
Strontium \({ }_{38}^{90} \mathrm{Sr}\) là một trong số các bụi phóng xạ nguy hiểm từ các vụ nổ hạt nhân. Chu kì bán rã của \({ }_{38}^{90} \mathrm{Sr}\) là \(T=28,8\) năm. Strontium khi bị bò ăn phải, sẽ tập trung trong sữa của bò và sẽ được lưu lại trong xương của những người uống sữa bò đó. Strontium \({ }_{38}^{90} \mathrm{Sr}\) khi nằm trong xương sẽ phát ra các tia phóng xạ có năng lượng lớn, phá hủy tủy xương và do đó làm suy yếu sự sản xuất tế bào hồng cầu. Strontium \({ }_{38}^{90} \mathrm{Sr}\) có khối lượng mol là \(M=90 \mathrm{~g} / \mathrm{mol}\). Lấy một năm có 365 ngày. Số Avogadro là \(N_{\mathrm{A}}=6,02 \cdot 10^{23} \mathrm{~mol}^{-1}\).
Strontium \({ }_{38}^{90} \mathrm{Sr}\) là một trong số các bụi phóng xạ nguy hiểm từ các vụ nổ hạt nhân. Chu kì bán rã của \({ }_{38}^{90} \mathrm{Sr}\) là \(T=28,8\) năm. Strontium khi bị bò ăn phải, sẽ tập trung trong sữa của bò và sẽ được lưu lại trong xương của những người uống sữa bò đó. Strontium \({ }_{38}^{90} \mathrm{Sr}\) khi nằm trong xương sẽ phát ra các tia phóng xạ có năng lượng lớn, phá hủy tủy xương và do đó làm suy yếu sự sản xuất tế bào hồng cầu. Strontium \({ }_{38}^{90} \mathrm{Sr}\) có khối lượng mol là \(M=90 \mathrm{~g} / \mathrm{mol}\). Lấy một năm có 365 ngày. Số Avogadro là \(N_{\mathrm{A}}=6,02 \cdot 10^{23} \mathrm{~mol}^{-1}\).
Hằng số phóng xạ của \({ }_{38}^{90} \mathrm{Sr}\) là \(\lambda=7,63 \cdot 10^{-10} \mathrm{~s}^{-1}\)
Khi một hạt nhân \({ }_{38}^{90} \mathrm{Sr}\) phóng xạ \(\beta^{-}\), sản phẩm phân rã là một hạt nhân có 37 proton và 53 neutron
Khối lượng \({ }_{38}^{90} \mathrm{Sr}\) tích tụ trong xương sẽ giảm bớt \(20 \%\) so với ban đầu sau thời gian \(t=15\) năm
Độ phóng xạ của lượng \({ }_{38}^{90} \mathrm{Sr}\) có khối lượng \(m=0,0145 \mu \mathrm{~g}\) có giá trị xấp xỉ \(H=74,0 \mathrm{kBq}\)
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
a) Hằng số phân ra của \({ }_{38}^{90} \mathrm{Sr}\) là
\( \lambda=\frac{\ln 2}{T}=\frac{\ln 2}{28,8 \cdot 365 \cdot 24 \cdot 3600}=7,63 \cdot 10^{-10} \mathrm{~s}^{-1} \)
b) Phương trình phân rã \(\beta^{-}\)của \({ }_{38}^{90} \mathrm{Sr}\) là
\( { }_{38}^{90} S r \rightarrow{ }_{-1}^{0} e+{ }_{Z}^{A} X . \)
Dùng định luật bảo toàn số nuclon và định luât bảo toàn điện tích ta được
\( \left\{\begin{array} { c } { 9 0 = 0 + A }\\ { 3 8 = - 1 + Z } \end{array} \rightarrow \left\{\begin{array}{l} A=90 \\Z=39 \end{array} \rightarrow{ }_{Z}^{A} X \equiv{ }_{39}^{90} Y .\right.\right. \)
c) Độ giảm tỉ đối của \({ }_{38}^{90} \mathrm{Sr}\) có trong xuơng nguờo i sau thời gian \(t=15\) năm là
\( \frac{\Delta m}{m_{0}}=\frac{m-m_{0}}{m_{0}}=\frac{m}{m_{0}}-1=\frac{m_{0} \cdot 2^{-\frac{t}{T}}}{m_{0}}-1=2^{-\frac{t}{T}}-1=2^{-\frac{15}{28,8}}-1 \approx-30,3 \% \)
d) Độ phóng xạ của luợng \({ }_{38}^{90} \mathrm{Sr}\) có khối lượng \(m=0,0145 \mu \mathrm{~g}\) là
\(\)
\begin{aligned}
H=\lambda N=\frac{\ln 2}{T} \cdot \frac{m}{M} \cdot N_{A}= & \frac{\ln 2}{28,8 \cdot 365 \cdot 24 \cdot 3600} \cdot \frac{0,0145 \cdot 10^{-6}}{90} \cdot 6,02 \cdot 10^{23}
& \approx 74020 \mathrm{~Bq} \approx 74,0 \mathrm{kBq}
\end{aligned}
\(\)
Tuyển Tập Đề Thi Tham Khảo Tốt Nghiệp THPT Năm 2025 - Vật Lí - Bộ Đề 01 là tài liệu ôn tập quan trọng dành cho học sinh lớp 12, giúp các em rèn luyện kỹ năng làm bài và chuẩn bị tốt nhất cho kỳ thi tốt nghiệp THPT 2025. Bộ đề được biên soạn theo định hướng của Bộ GD ĐT, bám sát chương trình học, bao gồm các chủ đề quan trọng như cơ học, điện học, quang học, dao động và sóng, vật lý hạt nhân… Hệ thống câu hỏi trắc nghiệm phong phú, được thiết kế theo nhiều mức độ từ nhận biết, thông hiểu đến vận dụng và vận dụng cao, giúp học sinh làm quen với cấu trúc đề thi và phát triển kỹ năng phân tích, tư duy logic. Mỗi đề thi đều có đáp án chi tiết và hướng dẫn giải cụ thể, hỗ trợ học sinh tự đánh giá năng lực, xác định điểm mạnh và cải thiện điểm yếu trong quá trình ôn tập.
Câu hỏi liên quan
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
[I] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
Which of the following best paraphrases the sentence in paragraph 4:
"Social experience is essential to successful brain development in babies."
Read the following advertisement and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 1 to 6.
KEEPING PETS – THE PERFECT COMPANION!
Are you thinking about (1) _____ a pet? Pets bring joy and companionship into our lives, making each day more exciting and (2) _____. Imagine coming home to a loyal dog or a playful cat. They are more than just animals—they are (3) _____ for you and your family.
Keeping pets requires responsibility, but the rewards are immeasurable. Choose a pet (4) _____ your lifestyle and home environment. For example, a small apartment is ideal for cats, while dogs might need more space to roam.
Remember, pets thrive (5) _____ love, care, and proper training. Taking the time to (6) _____ their needs is essential for a happy and healthy pet.
Start your journey to unconditional love with the perfect pet today!
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
The dollar is one of the most recognizable currencies in the world, renowned for its widespread use and influence. However, its origins trace back to Europe, where the term "dollar" evolved from the word "thaler," a silver coin first minted in the 16th century in the Bohemian region of Joachim’s. These coins became a reliable standard of trade across Europe due to their consistent silver content and quality. When European settlers journeyed to the Americas, they brought the concept of the "dollar" with them, setting the stage for its adoption in the New World.
In 1792, the United States Congress passed the Coinage Act, marking a pivotal moment in American monetary history. This act established the dollar as the country's official currency and defined its value in terms of silver and gold, aiming to create a stable and trustworthy monetary system. For much of its early history, the dollar was backed by precious metals, ensuring confidence in its value. However, in the 20th century, the dollar transitioned to a fiat currency system, meaning its value was no longer tied to gold or silver but backed by the US government's credibility. This shift allowed for more flexibility in managing the economy and implementing monetary policies.
The dollar's rise to global prominence began after World War II with the Bretton Woods Agreement of 1944. This accord pegged many international currencies to the US dollar, which was in turn linked to gold. Additionally, the agreement established the dollar as the world's primary reserve currency. Even after the collapse of the Bretton Woods system in the 1970s, the dollar maintained its dominance due to the strength and stability of the US economy.
Today, the dollar serves not just as a currency but as a symbol of economic power and reliability. It is used extensively in global trade, international investments, and as a benchmark for evaluating other currencies. Despite competition from emerging currencies like the euro and the Chinese yuan, the dollar remains at the heart of the global financial system, reflecting its enduring influence.
In which paragraph does the writer mention the historical foundation of the dollar's global dominance?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
[I] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
Which of the following is TRUE according to the passage?
Read thefollowing passage and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanksfrom 18 to 22.
Peer pressure, (18) ________, can have both positive and negative effects. For instance, when surrounded by motivated peers, (19) ________. Positive peer pressure can be a great motivator, as peers who excel in academics or extracurricular activities can inspire others to follow suit. However, peer pressure can also lead to negative outcomes. The influence of friends who engage in risky behaviors, such as skipping school or using substances, can encourage others to make poor decisions. Studies have shown that teenagers are more likely to take risks in the presence of their peers because they feel more confident when surrounded by others.
While peer pressure is often associated with negative behavior, (20) ________. For example, students may be encouraged to excel in their studies or participate in volunteer activities due to the positive influence of their peers. However, it is important to develop strong decision-making skills and self-confidence (21) ________.
Parents and educators play a key role in helping young people navigate peer pressure. By teaching young people how to recognize both positive and negative peer pressure, and how to make independent, thoughtful decisions, parents and educators can help ensure that students thrive in a healthy, supportive environment. Encouraging open communication, providing advice on how to stay true to one's values, and helping students develop self-confidence are all crucial aspects of this process.
In conclusion, peer pressure is a powerful influence. (22) ________, teenagers can succeed and grow in a positive social environment.
Mark the letter A, B, C or D to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17
a. Knowing the flood risk level in your area is the first step in staying prepared, as it allows you to anticipate potential dangers and take precautions in advance.
b. Additionally, securing important documents, such as identification papers and insurance policies, in waterproof containers can save you from significant financial and administrative troubles.
c. Flood safety requires careful planning and awareness to minimize risks, especially in regions prone to heavy rainfall or rising water levels.
d. It’s crucial to create an emergency kit with essentials like food, water, a flashlight, and a first-aid kit in case you need to evacuate on short notice.
e. In summary, understanding your local flood risks and taking proactive steps, such as preparing supplies and protecting valuables, can help ensure your safety during flood situations.
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
WELCOME TO YOUR NEW CITY!
Moving to a new city can be both exciting and overwhelming. Whether you're here for work, study, or a fresh start, our guide will help you settle in quickly and enjoy everything the city has to offer.
First, check out the public transport system. Unlike (7) _____ cities you've lived in; this one has a highly efficient network that connects all major areas. If you're unsure about routes, you can (8) _____ the official app for schedules and maps.
For work and leisure, this city is home to many opportunities in technology, education, and healthcare. It's a hub for (9) _____ and growth!
(10) _____ struggling to find parking, consider biking or using ride-share services—eco-friendlier and more stress-free!
Also, there are many exciting events happening year-round, from music festivals to art exhibitions.
Finally, don't forget to visit our iconic landmarks, including the new (11) _____ that opened downtown—a true architectural (12) _____.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
[I] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
Which of the following best summarizes paragraph 4?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
[I] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
The phrase “gain an edge” in the sentence is closest in meaning to:
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
The dollar is one of the most recognizable currencies in the world, renowned for its widespread use and influence. However, its origins trace back to Europe, where the term "dollar" evolved from the word "thaler," a silver coin first minted in the 16th century in the Bohemian region of Joachim’s. These coins became a reliable standard of trade across Europe due to their consistent silver content and quality. When European settlers journeyed to the Americas, they brought the concept of the "dollar" with them, setting the stage for its adoption in the New World.
In 1792, the United States Congress passed the Coinage Act, marking a pivotal moment in American monetary history. This act established the dollar as the country's official currency and defined its value in terms of silver and gold, aiming to create a stable and trustworthy monetary system. For much of its early history, the dollar was backed by precious metals, ensuring confidence in its value. However, in the 20th century, the dollar transitioned to a fiat currency system, meaning its value was no longer tied to gold or silver but backed by the US government's credibility. This shift allowed for more flexibility in managing the economy and implementing monetary policies.
The dollar's rise to global prominence began after World War II with the Bretton Woods Agreement of 1944. This accord pegged many international currencies to the US dollar, which was in turn linked to gold. Additionally, the agreement established the dollar as the world's primary reserve currency. Even after the collapse of the Bretton Woods system in the 1970s, the dollar maintained its dominance due to the strength and stability of the US economy.
Today, the dollar serves not just as a currency but as a symbol of economic power and reliability. It is used extensively in global trade, international investments, and as a benchmark for evaluating other currencies. Despite competition from emerging currencies like the euro and the Chinese yuan, the dollar remains at the heart of the global financial system, reflecting its enduring influence.
In which paragraph does the writer mention the dollar’s shift away from a precious metal standard?
Read thefollowing passage and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanksfrom 18 to 22.
Peer pressure, (18) ________, can have both positive and negative effects. For instance, when surrounded by motivated peers, (19) ________. Positive peer pressure can be a great motivator, as peers who excel in academics or extracurricular activities can inspire others to follow suit. However, peer pressure can also lead to negative outcomes. The influence of friends who engage in risky behaviors, such as skipping school or using substances, can encourage others to make poor decisions. Studies have shown that teenagers are more likely to take risks in the presence of their peers because they feel more confident when surrounded by others.
While peer pressure is often associated with negative behavior, (20) ________. For example, students may be encouraged to excel in their studies or participate in volunteer activities due to the positive influence of their peers. However, it is important to develop strong decision-making skills and self-confidence (21) ________.
Parents and educators play a key role in helping young people navigate peer pressure. By teaching young people how to recognize both positive and negative peer pressure, and how to make independent, thoughtful decisions, parents and educators can help ensure that students thrive in a healthy, supportive environment. Encouraging open communication, providing advice on how to stay true to one's values, and helping students develop self-confidence are all crucial aspects of this process.
In conclusion, peer pressure is a powerful influence. (22) ________, teenagers can succeed and grow in a positive social environment.
Mark the letter A, B, C or D to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17
a. Young marriage, defined as marrying before the age of 25, remains a common practice in many cultures, influenced by traditions, beliefs, and family expectations.
b. Critics point out that young couples often face issues like financial struggles, lack of maturity, and fewer opportunities for education or career advancement.
c. Proponents argue that marrying young helps couples build strong emotional bonds and grow together through shared life experiences.
d. Studies show that while the global rate of young marriages has declined in the past decade, it is still widely practiced, particularly in rural and traditional settings.
e. In summary, young marriage offers both benefits and challenges, requiring thoughtful consideration to ensure a stable and fulfilling partnership.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
The dollar is one of the most recognizable currencies in the world, renowned for its widespread use and influence. However, its origins trace back to Europe, where the term "dollar" evolved from the word "thaler," a silver coin first minted in the 16th century in the Bohemian region of Joachim’s. These coins became a reliable standard of trade across Europe due to their consistent silver content and quality. When European settlers journeyed to the Americas, they brought the concept of the "dollar" with them, setting the stage for its adoption in the New World.
In 1792, the United States Congress passed the Coinage Act, marking a pivotal moment in American monetary history. This act established the dollar as the country's official currency and defined its value in terms of silver and gold, aiming to create a stable and trustworthy monetary system. For much of its early history, the dollar was backed by precious metals, ensuring confidence in its value. However, in the 20th century, the dollar transitioned to a fiat currency system, meaning its value was no longer tied to gold or silver but backed by the US government's credibility. This shift allowed for more flexibility in managing the economy and implementing monetary policies.
The dollar's rise to global prominence began after World War II with the Bretton Woods Agreement of 1944. This accord pegged many international currencies to the US dollar, which was in turn linked to gold. Additionally, the agreement established the dollar as the world's primary reserve currency. Even after the collapse of the Bretton Woods system in the 1970s, the dollar maintained its dominance due to the strength and stability of the US economy.
Today, the dollar serves not just as a currency but as a symbol of economic power and reliability. It is used extensively in global trade, international investments, and as a benchmark for evaluating other currencies. Despite competition from emerging currencies like the euro and the Chinese yuan, the dollar remains at the heart of the global financial system, reflecting its enduring influence.
Which of the following is TRUE according to the passage?
Read the following advertisement and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 1 to 6.
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Are you tired of digital photos sitting on your phone or computer? Turn them into beautiful custom photo books with our easy-to-use platform. Our service ___(1)___ you to upload, organize, and design your own photo book, creating a unique keepsake to treasure forever. You can ___(2)___ between different layouts, themes, and covers to make your book truly special. With our high-quality printing, your memories will ___(3)___ vibrant and long-lasting. Plus, our photo books make great gifts for family and friends. Don't ___(4)___ your memories – capture them in a book you'll love to ___(5)___ for years to come. Start designing today and ___(6)___ 20% off your first order!
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
WELCOME TO YOUR NEW CITY!
Moving to a new city can be both exciting and overwhelming. Whether you're here for work, study, or a fresh start, our guide will help you settle in quickly and enjoy everything the city has to offer.
First, check out the public transport system. Unlike (7) _____ cities you've lived in; this one has a highly efficient network that connects all major areas. If you're unsure about routes, you can (8) _____ the official app for schedules and maps.
For work and leisure, this city is home to many opportunities in technology, education, and healthcare. It's a hub for (9) _____ and growth!
(10) _____ struggling to find parking, consider biking or using ride-share services—eco-friendlier and more stress-free!
Also, there are many exciting events happening year-round, from music festivals to art exhibitions.
Finally, don't forget to visit our iconic landmarks, including the new (11) _____ that opened downtown—a true architectural (12) _____.
Read the following advertisement and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 1 to 6.
KEEPING PETS – THE PERFECT COMPANION!
Are you thinking about (1) _____ a pet? Pets bring joy and companionship into our lives, making each day more exciting and (2) _____. Imagine coming home to a loyal dog or a playful cat. They are more than just animals—they are (3) _____ for you and your family.
Keeping pets requires responsibility, but the rewards are immeasurable. Choose a pet (4) _____ your lifestyle and home environment. For example, a small apartment is ideal for cats, while dogs might need more space to roam.
Remember, pets thrive (5) _____ love, care, and proper training. Taking the time to (6) _____ their needs is essential for a happy and healthy pet.
Start your journey to unconditional love with the perfect pet today!
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
WELCOME TO YOUR NEW CITY!
Moving to a new city can be both exciting and overwhelming. Whether you're here for work, study, or a fresh start, our guide will help you settle in quickly and enjoy everything the city has to offer.
First, check out the public transport system. Unlike (7) _____ cities you've lived in; this one has a highly efficient network that connects all major areas. If you're unsure about routes, you can (8) _____ the official app for schedules and maps.
For work and leisure, this city is home to many opportunities in technology, education, and healthcare. It's a hub for (9) _____ and growth!
(10) _____ struggling to find parking, consider biking or using ride-share services—eco-friendlier and more stress-free!
Also, there are many exciting events happening year-round, from music festivals to art exhibitions.
Finally, don't forget to visit our iconic landmarks, including the new (11) _____ that opened downtown—a true architectural (12) _____.
Mark the letter A, B, C or D to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17
Dear Mary,
a. I hope you understand how important it is for everyone in the neighborhood to maintain a peaceful environment.
b. Thank you for your understanding, and I would appreciate it if you could be more mindful in the future.
c. However, the loud noise from your parties over the past few weekends has been quite disruptive.
d. I understand that everyone enjoys celebrating and having fun, and I respect your right to do so.
e. If you have any suggestions or need help organizing quieter activities, feel free to reach out.
Bye,
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions
[I] A newborn baby can see, hear and feel. By the age of five, a child can talk, ride a bike and invent imaginary friends. How does this development happen? [II]We don't understand the way language, thinking and planning develop very well. [III]Now scientists are using new technology to ‘see’ into children's brains. And they are discovering new information about the way a baby's brain develops. [IV]
A study in 2010 showed that children who were afforded more focus often gained an edge in IQ. The brain of a newborn infant contains nearly a hundred billion neurons. This number is comparable to that of an adult's brain. As they mature, an infant assimilates information through the sensory modalities of sight, hearing, smell, taste, and touch. This information fosters intricate connections between different regions of the brain. By the age of three, there are approximately a hundred trillion synaptic connections.
One experiment looked at images of babies' brains while they were listening to different sounds. The sounds were in different sequences. For example, one sequence was mu-ba-ba. This is the pattern ‘A-B-B’. Another sequence was mu-ba-ge. This is the pattern ‘A-B-C’. The images showed that the part of the brain responsible for speech was more active during ‘A-B-B’ patterns. This shows that babies can tell the difference between different patterns. This experiment is interesting because sequences of words are important to grammar and meaning. Compare two sentences with the same words in a different order: ‘John killed the bear’ is very different from ‘The bear killed John.’ So babies are starting to learn grammatical rules from the beginning of life.
Researchers also know that babies need to hear a lot of language in order to understand grammar rules. But there is a big difference between listening to television, audiobooks or the internet, and interacting with people. One study compared two groups of nine-month-old American babies. One group watched videos of Mandarin Chinese sounds. In the other group, people spoke the same sounds to the babies. The test results showed that the second group could recognize different sounds, however, the first group learned nothing. The scientist, Patricia Kuhl, said this result was very surprising. It suggests that social experience is essential to successful brain development in babies.
The word “recognize” in paragraph 4 is OPPOSITE in meaning to:
Read the following leaflet and mark the letter A, B, C or D on your answer sheet to indicate the option that bestfits each of the numbered blanks from 7 to 12.
WELCOME TO YOUR NEW CITY!
Moving to a new city can be both exciting and overwhelming. Whether you're here for work, study, or a fresh start, our guide will help you settle in quickly and enjoy everything the city has to offer.
First, check out the public transport system. Unlike (7) _____ cities you've lived in; this one has a highly efficient network that connects all major areas. If you're unsure about routes, you can (8) _____ the official app for schedules and maps.
For work and leisure, this city is home to many opportunities in technology, education, and healthcare. It's a hub for (9) _____ and growth!
(10) _____ struggling to find parking, consider biking or using ride-share services—eco-friendlier and more stress-free!
Also, there are many exciting events happening year-round, from music festivals to art exhibitions.
Finally, don't forget to visit our iconic landmarks, including the new (11) _____ that opened downtown—a true architectural (12) _____.
